[PATCH 4.14 002/125] spi: spi-fsl-dspi: Adding shutdown hook

From: Greg Kroah-Hartman
Date: Mon Jul 20 2020 - 11:44:34 EST


From: Peng Ma <peng.ma@xxxxxxx>

[ Upstream commit dc234825997ec6ff05980ca9e2204f4ac3f8d695 ]

We need to ensure dspi controller could be stopped in order for kexec
to start the next kernel.
So add the shutdown operation support.

Signed-off-by: Peng Ma <peng.ma@xxxxxxx>
Link: https://lore.kernel.org/r/20200424061216.27445-1-peng.ma@xxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/spi/spi-fsl-dspi.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index ca013dd4ff6bb..d5b56b7814fe3 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -49,6 +49,9 @@
#define SPI_MCR_PCSIS (0x3F << 16)
#define SPI_MCR_CLR_TXF (1 << 11)
#define SPI_MCR_CLR_RXF (1 << 10)
+#define SPI_MCR_DIS_TXF (1 << 13)
+#define SPI_MCR_DIS_RXF (1 << 12)
+#define SPI_MCR_HALT (1 << 0)

#define SPI_TCR 0x08
#define SPI_TCR_GET_TCNT(x) (((x) & 0xffff0000) >> 16)
@@ -1074,6 +1077,24 @@ static int dspi_remove(struct platform_device *pdev)
return 0;
}

+static void dspi_shutdown(struct platform_device *pdev)
+{
+ struct spi_controller *ctlr = platform_get_drvdata(pdev);
+ struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);
+
+ /* Disable RX and TX */
+ regmap_update_bits(dspi->regmap, SPI_MCR,
+ SPI_MCR_DIS_TXF | SPI_MCR_DIS_RXF,
+ SPI_MCR_DIS_TXF | SPI_MCR_DIS_RXF);
+
+ /* Stop Running */
+ regmap_update_bits(dspi->regmap, SPI_MCR, SPI_MCR_HALT, SPI_MCR_HALT);
+
+ dspi_release_dma(dspi);
+ clk_disable_unprepare(dspi->clk);
+ spi_unregister_controller(dspi->master);
+}
+
static struct platform_driver fsl_dspi_driver = {
.driver.name = DRIVER_NAME,
.driver.of_match_table = fsl_dspi_dt_ids,
@@ -1081,6 +1102,7 @@ static struct platform_driver fsl_dspi_driver = {
.driver.pm = &dspi_pm,
.probe = dspi_probe,
.remove = dspi_remove,
+ .shutdown = dspi_shutdown,
};
module_platform_driver(fsl_dspi_driver);

--
2.25.1